DEV_BROADCAST_VOLUME structure (dbt.h)

Contains information about a logical volume.

Syntax

typedef struct _DEV_BROADCAST_VOLUME {
  DWORD dbcv_size;
  DWORD dbcv_devicetype;
  DWORD dbcv_reserved;
  DWORD dbcv_unitmask;
  WORD  dbcv_flags;
} DEV_BROADCAST_VOLUME;

Members

dbcv_size

The size of this structure, in bytes.

dbcv_devicetype

Set to DBT_DEVTYP_VOLUME (2).

dbcv_reserved

Reserved; do not use.

dbcv_unitmask

The logical unit mask identifying one or more logical units. Each bit in the mask corresponds to one logical drive. Bit 0 represents drive A, bit 1 represents drive B, and so on.

dbcv_flags

This parameter can be one of the following values.

Value Meaning
DBTF_MEDIA
0x0001
Change affects media in drive. If not set, change affects physical device or drive.
DBTF_NET
0x0002
Indicated logical volume is a network volume.

Remarks

Although the dbcv_unitmask member may specify more than one volume in any message, this does not guarantee that only one message is generated for a specified event. Multiple system features may independently generate messages for logical volumes at the same time.

Messages for media arrival and removal are sent only for media in devices that support a soft-eject mechanism. For example, applications will not see media-related volume messages for floppy disks.

Messages for network drive arrival and removal are not sent whenever network commands are issued, but rather when network connections will disappear as the result of a hardware event.

Requirements

Requirement Value
Minimum supported client Windows XP
Minimum supported server Windows Server 2003
Header dbt.h

See also

DEV_BROADCAST_HDR

WM_DEVICECHANGE